【摘要】 测定了春季香溪河库湾的水温(WT)、pH、HCO3-浓度、溶氧(DO)及叶绿素a(Chl-a)浓度等参数.根据化学平衡和亨利定律计算二氧化碳分压(pCO2),以薄层扩散模型计算碳通量.结果表明,香溪河库湾春季表层水体pCO2在8.34～168.70μatm间波动,平均为49.01μatm.空间上,pCO2自上游到河口呈明显上升趋势,Chl-a浓度则逐渐下降.时间上,昼夜pCO2在74.43～168.70μatm间波动,平均为117.92μatm,Chl-a浓度在2.22～4.55 mg.m-3之间,平均为3.04 mg.m-3.香溪河库湾春季表层水体pCO2与Chl-a浓度之间存在极显著的负相关关系(r=-0.844,P<0.01),浮游植物光合作用是pCO2的主要影响因子.香溪河库湾春季是CO2的汇,CO2吸收速率为-35.17 mmol.(m2.d)-1.更多还原

【Abstract】 Water temperature(WT),pH,HCO-3,dissolved oxygen and the concentration of Chl-a in Xiangxi Bay were measured in spring.The partial pressure of carbon dioxide was calculated by the chemical balance and Henry’s Law while CO2 flux by the thin-layer diffusion model.Results showed that pCO2 of surface water in Xiangxi Bay varied from 8.34μatm to 168.70 μatm with a mean of 49.01 μatm.pCO2 increased along the stream with Chl-a decreased from upstream to the estuary.The mean of pCO2 was 117.92 μatm on the diurnal scale,ranging from 74.43 μatm to 168.70 μatm,and the mean concentration of Chl-a was 3.04 mg·m-3 with the range from 2.22 mg·m-3 to 4.55 mg·m-3.There were statistically significant negative correlations between values for pCO2 and Chl-a(r=-0.844,P<0.01).Phytoplankton photosynthesis in Xiangxi Bay played a crucial role in the spatial and temporal distribution of pCO2.The undersaturation observed suggests that surface waters in Xiangxi Bay represented a sink for atmospheric CO2 in spring,and the exchange rate of CO2 was estimated to be-35.17 mmol·(m2·d)-1.更多还原